Secondary cell

Abstract

Provided is a secondary cell in which the production takt time can be improved, airtightness of a cell canister is exhibited, cell capacity can be increased, and excellent handling properties can be obtained. A secondary cell comprising an electrode group ( 1 ); an exterior case ( 11 ); and a cell canister ( 10 ) comprising the exterior case ( 11 ) and a lid member ( 12 ), the interior of which canister being filled with an electrolyte, and airtightness being achieved; the secondary cell being constituted such that the cell canister ( 10 ) comprises a electrode group accommodating part and a peripheral edge section in which the exterior case ( 11 ) and the lid member ( 12 ) are double-seamed and sealed; and the peripheral edge section is provided so as to bulge outward from the electrode group accommodating part, and has an appropriately sized corner R corresponding to the plate thickness of plates to be double-seamed and exhibiting airtightness.

1 . A secondary cell, comprising:
 an electrode group obtained by layering a positive electrode plate, a negative electrode plate, and a separator;   an exterior case for accommodating the electrode group, and a lid member for hermetically sealing the exterior case; and   a cell canister configured using the exterior case and the lid member, an interior of the cell canister being filled with an electrolyte;   the cell canister having a substantially cuboid electrode group accommodating part, and a peripheral edge section in which the exterior case and the lid member are double-seamed and sealed; and   the peripheral edge section being provided so as to bulge outward from the electrode group accommodating part, and having a corner R that is greater than a bend r of a corner section of the exterior case.   
     
     
         2 . The secondary cell according to  claim 1 ,
 the corner R being equal to or greater than double the bend r.   
     
     
         3 . The secondary cell according to  claim 1 ,
 the corner R being a corner R corresponding to the plate thickness of the double-seamed exterior case and lid member, and exhibiting airtightness.   
     
     
         4 . The secondary cell according to  claim 1 ,
 a double-seamed section provided so as to bulge outward from the electrode group accommodating part and protrude upward, and forming a step having a predetermined chuck wall height and being of a size allowing the electrode group accommodating part to fit therein.   
     
     
         5 . The secondary cell according to  claim 1 ,
 the peripheral edge section being provided upon four peripheral sides of the electrode group accommodating part being extended.   
     
     
         6 . The secondary cell according to  claim 1 ,
 the cell canister having an electrode group accommodating part provided with positive and negative external terminals installed respectively on two opposing side surfaces, the electrode group accommodating part fashioned to a rectangular profile having long sides and short sides; and   the peripheral edge section being provided upon primarily the short sides to which the external terminals are provided being extended.   
     
     
         7 . The secondary cell according to  claim 1 ,
 the cell canister having an electrode group accommodating part provided with positive and negative external terminals installed respectively on two opposing side surfaces, the electrode group accommodating part fashioned to a rectangular profile having long sides and short sides; and   the peripheral edge section being provided upon primarily the long sides to which the external terminals are not provided being extended.   
     
     
         8 . The secondary cell according to  claim 1 ,
 the plate thickness of the exterior case and the plate thickness of the lid member being a thickness of about 0.8 to 1.0 mm at which predetermined cell canister strength is exhibited, the corner R being about 15 mm or more.